The present invention relates to an integrated circuit device and an electronic instrument.
In recent years, a high-speed serial transfer interface such as low voltage differential signaling (LVDS) has attracted attention as an interface aiming at reducing EMI noise or the like. In such a high-speed serial transfer, a transmitter circuit transmits serialized data by using differential signals, and a receiver circuit differentially amplifies the differential signals to realize data transfer (JP-A-2001-222249).
A portable telephone generally includes a first instrument section provided with buttons for inputting a telephone number or characters, a second instrument section provided with a display panel or a camera, and a connection section such as a hinge which connects the first and second instrument sections. Therefore, the number of interconnects passing through the connection section can be reduced by transferring data between a first substrate provided in the first instrument section and a second substrate provided in the second instrument section by serial transfer using differential signals.
A display driver (LCD driver) is an integrated circuit device which drives a display panel such as a liquid crystal panel. In order to realize the high-speed serial transfer between the first and second instrument sections, a high-speed interface circuit which transfers data through a serial bus must be incorporated in the display driver.
However, when mounting the integrated circuit device as the display driver by using a chip-on-glass (COG) technology, the high-speed serial transfer signal quality deteriorates due to contact resistance of a bump as an external connection terminal.
A reduction in chip size is required for the display driver in order to reduce cost. However, the size of the display panel incorporated in a portable telephone or the like is almost constant. Therefore, if the chip size is reduced by merely shrinking the integrated circuit device as the display driver by using a microfabrication technology, it becomes difficult to mount the integrated circuit device.